This 1″ Sch 80 PVC True Union Ball Check Valve, VITON, (SOC x SOC) prevents flow from going in one direction using a ball inside the valve that seals with back pressure. Socket connections are joined to pipe of the same diameter with solvent welding. Sch 80 PVC is robust and durable, perfect for commercial and industrial applications. VITON seals provide increased temperature resistance than EPDM seals and recommended for exposure to oils, gasoline and aggressive chemicals. Petram PVC has all the schedule 80 PVC and CPVC fittings and valves you need for your project.